Back: Superficial and Deep Muscles

Question 1

Superficial Back Muscles

Answer 1

• Posterior axio-appendicular muscles

- Innervated by anterior (ventral) rami

Question 2

Intrinsic (Deep) Back Muscles

Answer 2

• Attach along axial skeleton
• Innervated by dorsal rami
• Movement and control of vertebral column and skull
• Multiple layers

Question 3

Posterior Axio-appendicular Muscles (Superficial)

Answer 3

• Trapezius
• Latissimus Dorsi
• Levator scapulae (deep to traps/lats)
• Rhomboid major and minor (deep to traps/lats)
• Serratus posterior (deep to traps/lats)

Question 4

Trapezius Muscle Parts

Answer 4

• Superior (descending): elevation, rotation
• Middle: retraction
• Inferior (ascending): depression, rotation

Question 5

Trapezius Proximal Attachment (Origin)

Answer 5

• Medial 1/3 of superior nuchal line
• EOP
• Nuchal ligament
• SPs of C7-T12

Question 6

Trapezius Distal Attachment (Insertion)

Answer 6

• lateral 1/3 of clavicle, acromion and scapular spine

Question 7

Trapezius Innervation

Answer 7

• Spinal accessory nerve (motor)

- C3,4 spinal nerves (pain and proprioception)

Question 8

Trapezius Weakness or CN XI Injury

Answer 8

• Weakness in shrugging, impaired abduction/arm elevation, shoulder drooping

Question 9

Latissimus Dorsi

Answer 9

• Expansive muscle

- Forms posterior axillary fold

Question 10

Latissimus Dorsi Proximal Attachment (Origin)

Answer 10

• SPs of T7-L5
• Thoracolumbar fascia
• Iliac crest
• Inferior 3 or 4 ribs
• Inferior angle of the scapula

Question 11

Latissimus Dorsi Distal Attachment (Insertion)

Answer 11

• Humerus (floor of intertubercular sulcus)

Question 12

Latissimus Dorsi Innervation

Answer 12

• Thoracodorsal nerve

Question 13

Latissimus Dorsi Function

Answer 13

• Extends, adducts, medial rotation of humerus

- Pull-up type motions

Question 14

Triangle of Auscultation

Answer 14

• Trapezius
• Latissimus Dorsi
• Medial border of scapulae
• (Borders of the three)

Question 15

Levator Scapulae Proximal Attachment (Origin)

Answer 15

• Posterior tubercles of C1-4 TPs

Question 16

Rhomboids (Minor and Major) Proximal Attachment (Origin)

Answer 16

• Nuchal ligament, C7 – T5 SPs

Question 17

Rhomboid Minor, Rhomboid Major, and Levator Scapulae Distal Attachment (Insertion)

Answer 17

• Medial scapular border

Question 18

Rhomboid Minor, Rhomboid Major, and Levator Scapulae Innervation

Answer 18

• Dorsal scapular nerve (C4,5) – motor

- C3,4: proprioception

Question 19

Rhomboid Minor, Rhomboid Major, and Levator Scapulae Function

Answer 19

• Elevate and rotate scapula (glenoid rotates inferiorly)

- Retract scapula

Question 20

Serratus Posterior Superior

Answer 20

• Covered by rhomboids
• Spinous processes of C7 – T3 and ligamentum nuchae
• Inserts rib 2-5

Question 21

Serratus Posterior Inferior

Answer 21

• Covered by latissimus dorsi
• Origin: SPs of T11-L2
• Inserts: lower 4 ribs

Question 22

Deep Back Muscles (Intrinsic Back Muscles)

Answer 22

• Supplied by dorsal primary rami
• Extend from pelvis to cranium
• Enclosed by thoracolumbar fascia

Question 23

Layers of Deep Back Muscles

Answer 23

• Superficial
• Intermediate
• Deep

Question 24

Superficial Intrinsic (Deep) Back Muscles

Answer 24

• Splenius capitis

- Splenius cervicis

Question 25

Intermediate Intrinsic (Deep) Back Muscles

Answer 25

- Erector Spinae (Sacrospinalis) | - Named by location/attachment

Question 26

Deep Intrinsic (Deep) Back Muscles

Answer 26

- Semispinali - Multifidus - Rotatores (Transversospinalis) - Interspinalis - Intertransversarii - Levatores costarum (Interspinalis)

Question 27

Erector Spinae Muscles

Answer 27

- Iliocostalis - Longissimus - Spinalis

Question 28

Splenius Capitis and Splenius Cervicis Proximal Attachment (Origin)

Answer 28

- Ligamentum nuchae and SPs of C7 – T6

Question 29

Splenius Capitis and Splenius Cervicis Distal Attachment (Insertion)

Answer 29

- TPs of C1-3 | - Mastoid process and lateral 1/3 of superior nuchal line of occipital bone

Question 30

Splenius Capitis and Splenius Cervicis Innervation

Answer 30

- Dorsal rami of cervical nerves

Question 31

Splenius Capitis and Splenius Cervicis Function

Answer 31

- Extension, lateral flexion and rotation of the head and neck

Question 32

Thoracolumbar Fascia

Answer 32

- Deep fascia that covers and encloses deep back muscles

Question 33

Transversospinalis Muscles

Answer 33

- Transverse process to spinous process (and lamina) | - Fill the gutter between SP and TP

Question 34

Multifidus

Answer 34

- Prominent in lumbar region - Also attach to mammillary processes - Span 2-4 segments

Question 35

Semispinalis

Answer 35

- Prominent in the cervical region | - Attaches to occiput

Question 36

Rotatores

Answer 36

- Best developed in thoracic region - Short (brevis) - Long (longus)

Question 37

Interspinalis, Intertransversarii, and Levator costarum

Answer 37

- Primarily serve a proprioceptive function | - High density of muscle spindles

Question 38

Interspinalis

Answer 38

- Between spinous processes

Question 39

Intertransversarii

Answer 39

- Between spinous processes

Question 40

Levator Costarum

Answer 40

- Tips of transverse processes to ribs

Question 41

Suboccipital Muscles

Answer 41

- Rectus capitis posterior minor (RCPm) - Rectus capitis posterior major (RCPM) - Obliquus capitis superior (OCS) - Obliquus capitis inferior (OCI)

Question 42

Suboccipital Triangle

Answer 42

- Superomedial: RCPM - Superolateral: OCS - Inferolateral: OCI - Floor: Posterior atlantooccipital membrane - Roof: Semispinalis muscle

Question 43

Suboccipital Triangle Content

Answer 43

- Vertebral artery - Suboccipital nerve (dorsal rami of C1) - Innervates suboccipital muscles

Question 44

Greater Occipital Nerve

Answer 44

- Dorsal rami of C2 - Not a triangle content - Innervates: - Semspinalis - Skin of upper neck and posterior head